<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>

<style>
    div{
        width: 100px;
        height: 100px;
        background-color: aqua;
        line-height: 100px
    }
</style>
<body>
    <p>Hello Html</p>
    <input type="text" placeholder="请输入用户名">
    <div style="">
        这是一个div
    </div>
    <p>Hello Html</p>
    <div style="">
        这是div2
    </div>
</body>
</html>